GT S197 General DiscussionThis section is for technical discussions pertaining specifically to the V8 variation of the 2005 and newer Ford Mustang.

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i.e. what does the naturally aspirated Coyote do better than an modern NA 351W?

Idle.

I'm serious. the Coyote makes 420 horsepower from 5.0 liters. It makes 420 hp all day, every day. It idles smoothly, has great throttle response across most of its RPM range, and has a fairly broad torque curve.

a 420 hp carbed 351W (5.8 liters) would need a hot cam and probably a single plane intake, so it would barely idle at all, would have little low-end pull, and would be a huge pain in the *** to drive on the street. oh, and if you have power brakes you'd probably need an auxiliary vacuum pump to make up for the lack of manifold vacuum. nobody would put up with a rough idle like

Sincere question: So the crate engines from Ford can't achieve their rated numbers in a streetable manner?
That seems odd but maybe true. I wouldn't know. I've never driven anything other than the 302 and the Modulars.

The HP achievable with the Coyote from Ford is fine by me... the Coyote Aluminator XS is rated North of 500 HP but the downer is torque... 386 ft lbs.

I'm more concerned with torque.

Thanks again!

Quote:

Originally Posted by jz78817

Idle.

I'm serious. the Coyote makes 420 horsepower from 5.0 liters. It makes 420 hp all day, every day. It idles smoothly, has great throttle response across most of its RPM range, and has a fairly broad torque curve.

a 420 hp carbed 351W (5.8 liters) would need a hot cam and probably a single plane intake, so it would barely idle at all, would have little low-end pull, and would be a huge pain in the *** to drive on the street. oh, and if you have power brakes you'd probably need an auxiliary vacuum pump to make up for the lack of manifold vacuum. nobody would put up with a rough idle like

So the crate engines from Ford can't achieve their rated numbers in a streetable manner?

Keep in mind the "351" crate motors offered by Ford Racing Parts are actually punched out to 427 cu. in. but yeah, they have aggressive cams and the "recommended intake" Edelbrock Super Victor is single-plane. Single plane intakes are generally used for mid- to top-end power, and you trade off low end.

Quote:

I'm more concerned with torque.

Horsepower= (Torque x RPM)/5252. If you have a carbed V8 and fixed cam timing/profile, you've got to decide what kind of engine you want. If you want low-end torque, you're going to need a calmer, shorter-duration cam and a dual-plane intake, with fairly small primaries on your carb. You'll make good low-end torque but your peak horsepower will not be that high. If you want a high-rpm circle track engine, you want a single-plan intake, a long duration/high lift cam, and a high-cfm carb. It'll make big hp numbers, but low end performance will be crap and it'll be a pain in the **** to drive around town.

When you have fuel injection, variable cam timing, and variable intake manifold geometry, the sky is the limit.

Quote:

The HP achievable with the Coyote from Ford is fine by me... the Coyote Aluminator XS is rated North of 500 HP but the downer is torque... 386 ft lbs.

yeah. see, that's the thing about torque/hp peaks; if you push the torque peak up to a higher RPM, your peak horsepower goes up (see the equation I wrote above.) The simple fact that the Aluminator makes the same peak torque as a stock 2012 5.0 but almost 100 more horsepower guarantees that the hp peak occurs at a higher RPM.

Kind of interesting, eh? They all make about the same peak torque. The key difference is in how the engines are tuned; e.g. where in the RPM range those peaks happen. The F-150 makes that 380 lb-ft at a lot lower RPM than the other two, so the peak hp is a lot lower at 360.

Keep in mind the "351" crate motors offered by Ford Racing Parts are actually punched out to 427 cu. in. but yeah, they have aggressive cams and the "recommended intake" Edelbrock Super Victor is single-plane. Single plane intakes are generally used for mid- to top-end power, and you trade off low end.

I know that the Coyote is probably enough HP and Torque but you know how it is...if we were all satisfied then there would never be a supercharger sold.

I just prefer NA vs FI but want more torque and would like to do something fun like run Carb'd engine in my S197.

eh, physics pretty much says that the Coyote is capped at about 400 lb-ft when naturally aspirated (go read up about BMEP if you want to know more.) Once you go forced induction, that's a new set of rules...

Quote:

Oh yeah I forgot to mention: Nice Notchback! I dig the 408. Is this yours?

Well, the power is in the heads basically.
The Coyote has a DOHC and it's a huge advantage over the old school 351.
But despite that, the 351 has the extra cubic inches and with good aftermarket flowing heads like AFR or Trick Flow (185cc) and good intake like an air gap or Victor Junior Edelbrock with matching roller cam you will match the Coyote hp and have more torque without going for a stroker kit.
Now a well built 408 out of a 351 block will spank the Coyote mill with no problems and still be easy to drive on the streets.

So OP, if you're looking for good torque naturally aspirated, the 351 will be better but make sure your State doesn't have the yearly inspection.

eh, physics pretty much says that the Coyote is capped at about 400 lb-ft when naturally aspirated (go read up about BMEP if you want to know more.) Once you go forced induction, that's a new set of rules...

I wish. Just some video I found on youtube.

Yeah 390 ft lbs torque seems to be about it, though Stang TV features a custom built Coyote using a Livernois block that laid down 624.9 horsepower recorded at 7,800 rpm. Peak torque of 462.3 lb-ft came at 6,200 rpm. The engine developed over 400 lb-ft of torque by 4,700 rpm. But the build and tune was radically different than a factory or even a factory reworked engine.

Quote:

Originally Posted by pascal

Well, the power is in the heads basically.
The Coyote has a DOHC and it's a huge advantage over the old school 351.
But despite that, the 351 has the extra cubic inches and with good aftermarket flowing heads like AFR or Trick Flow (185cc) and good intake like an air gap or Victor Junior Edelbrock with matching roller cam you will match the Coyote hp and have more torque without going for a stroker kit.
Now a well built 408 out of a 351 block will spank the Coyote mill with no problems and still be easy to drive on the streets.

Thanks Pascal. That's what I'm looking to achieve. It's less money that a new car...and in just about every instance a lot more fun. A civilized 408 would be the cat's ***.

Quote:

Originally Posted by pascal

So OP, if you're looking for good torque naturally aspirated, the 351 will be better but make sure your State doesn't have the yearly inspection.

You mean like California?
My Mustang turns 7 this year so I think I will have to get it smogged. I believe new cars are exempt for the first 6 yrs.

A roller cam makes it to where it's possible as long as it's not super radical.
A dual plane is more civilized I agree...
But I had that set up in my old Cougar with a "Z" roller cam from FRPP, AFR heads and a Holley 750 carb (with undersized primary jets).
A friend recommended that combo which I found odd but said he did this to his 69 Mustang and was a good daily driver. He was right.
I do have a 5spd tremec in my car though...
Since then, I put that engine in a 68 Fastback that was shipped over seas.
I have now a 342 stroker in the Cougar but it's just not the same...
I'm building a 408 at the moment and it will be matted to a 6spd (out of a Termie).

Pascal,
I've read about several 408 builds that sound ideal based on what I'd like hoping there might be some loophole under "custom car" smog exemptions but after reading up on the CA DMV site I can forget about that.

I've considered swapping my 4.6 for a Coyote which would certainly be a nice change but also considered keeping my 4.6 to stay true to the model and then do this...

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